Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 31
Filtrar
1.
RSC Adv ; 14(38): 28244-28259, 2024 Aug 29.
Artículo en Inglés | MEDLINE | ID: mdl-39234520

RESUMEN

In this work, ZnO nanoplates and Fe2O3 nanospindles were successfully fabricated via a simple hydrothermal method using inorganic salts as precursors. The ZnO/Fe2O3 hybrid was fabricated using a mechanical mixture of two different ZnO : Fe2O3 weight ratios to investigate the effect of weight ratio on catalytic properties. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images showed that ZnO nanoplates (NPls) are about 20 nm thick with lateral dimensions of 100 × 200 nm, and Fe2O3 nanospindles (NSs) are about 500 nm long and 50 nm wide. X-ray diffraction (XRD) patterns revealed the successful formation of the ZnO, Fe2O3, and ZnO/Fe2O3 samples and indicated that their crystallite sizes varied from 20 to 29 nm depending on the ZnO : Fe2O3 weight ratio. Ultraviolet-visible (UV-vis) spectra showed that the bandgap energies of ZnO and Fe2O3 were 3.15 eV and 2.1 eV, respectively. Energy dispersive X-ray spectroscopy (EDS) results revealed the successful combination of ZnO and Fe2O3. Photocatalytic activity of the materials was evaluated through the degradation of methylene blue (MB) in aqueous solution under green light-emitting diode (GLED) irradiation. The results indicated that the ZnO/Fe2O3 composite showed a remarkable enhanced degradation capacity compared to bare ZnO NPls and Fe2O3 NSs. The ZnO : Fe2O3 = 3 : 2 sample demonstrated the best performance among all samples under identical conditions with a degradation efficiency of 99.3% for MB after 85 min. The optimum photocatalytic activity of the sample with ZnO : Fe2O3 = 3 : 2 was nearly 3.6% higher than that of the pure ZnO sample and 1.12 times more than that of the pristine Fe2O3 sample. Moreover, the highest photo-degradation was obtained at a photocatalyst dosage of 0.25 g l-1 in dye solution.

3.
J Transl Autoimmun ; 8: 100238, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38496268

RESUMEN

Sjögren's syndrome (SS) is a systemic autoimmune pathology manifested mainly by a dry syndrome, intense asthenia and arthromyalgia. Systemic manifestations may also occur. Since 2019, immunosuppressant agents (IS) or biotherapies are recommended only for patients with systemic involvement. However, before 2019, in some cases, paucisymptomatic patients had been treated with IS/biotherapies, often off-label. Objective: We propose to evaluate the benefit and safety of using IS/biotherapy in patients with SS without systemic involvement. Methods: We retrospectively collected the clinical records of all patients with SS diagnosed according to ACR/EULAR diagnostic criteria followed up between January 1980 and October 2023 at Grenoble University Hospital (France). Results: Eighty-three patients were included: 64 with an initially non-systemic form. Of these patients with an initially non-systemic form, 24 were treated with IS/biotherapy. None of them developed secondary systematization, whereas 11 out of 40 patients in the untreated group did (p < 0.05). On the other hand, IS/biotherapy did not appear to improve dry syndrome. There were no serious adverse events. Conclusion: Early introduction of an IS/biotherapy treatment appears to provide a benefit for the patient without side effects.

4.
Sci Rep ; 14(1): 1349, 2024 01 16.
Artículo en Inglés | MEDLINE | ID: mdl-38228662

RESUMEN

Carbon sources are considered as critical input for the health and immunity of aquatic animals. The present study investigated the impact of different carbon sources on water quality parameters, carbon to nitrogen (C/N) ratio and microbial community in sediments, and health responses of marron (Cherax cainii) under laboratory conditions. Following one week of acclimation, 120 marron were randomly assigned to 12 experimental tanks. There were four treatments including one untreated control and three groups with carbon addition to maintain a C/N ratio of 12 maintained in culture water. Carbon supplementation groups included corn flour (CBC12), molasses (MBC12) and wheat flour (WBC12). At the end of the 60-day trial, MBC12 resulted in the highest sediment C/N ratio, followed by CBC12. Weight gain and specific growth rate were higher in MBC12, compared to control. The protease activity in marron hepatopancreas, total haemocyte count and lysozyme activity in haemolymph were highest in MBC12. Analysis of 16S rRNA sequence data of tank sediments revealed increased bacterial alpha diversity in MBC12 and WBC12. Proteobacteria was the most abundant phylum in MBC12 (88.6%), followed by control (82.4%) and CBC12 (72.8%). Sphingobium and Novosphingobium were the most abundant genera in control and MBC12 groups, respectively. Higher Aeromonas abundance in CBC12 and Flavobacterium in WBC12 were observed. Overall results indicated that MBC12 led to improved water quality, retaining high C/N ratio and enriched the bacterial populations in sediments resulting in improved growth and immune performance of marron.


Asunto(s)
Astacoidea , Harina , Animales , Astacoidea/fisiología , ARN Ribosómico 16S/genética , Triticum , Bacterias/genética , Sedimentos Geológicos , Carbono/farmacología
5.
Int J Infect Dis ; 139: 109-117, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37984763

RESUMEN

OBJECTIVES: SARS-CoV-2 transmission and epidemic potential is related to the population's immunity levels. As such, assessing different regions' preexisting immune responses to SARS-CoV-2 is important to understand the transmission potential of emerging SARS-CoV-2 variants. DESIGN: In 975 serum samples from Vietnam (2014 to 2019), anti-SARS-CoV-2 Immunoglobulin G levels were determined by enzyme-linked immunosorbent assay. Plaque reduction neutralization test (PRNT) was performed using Wuhan strain and variants of concern (VOCs). Cross-reactivity was confirmed by analyzing B-cell receptor (BCR) repertoire sequences and identifying BCR repertoire sequences-derived T-cell epitopes. RESULTS: Overall, 20.9% (n = 76/364) and 9.2% (n = 7) demonstrated SARS-CoV-2 neutralizing activity (PRNT50) against the Wuhan and Alpha strain, respectively. Neutralizing activity against Beta, Gamma, and Delta strains was absent (PRNT50<5) in all samples. Cross-reactive epitopes against SARS-CoV-2 and other coronavirus spike proteins were detected in the N-terminal domain, S2, and receptor-binding domain regions. CONCLUSIONS: Following BCR and major histocompatibility complex analysis, T-cell receptor-recognized epitope motif (TREM) among pathogenic coronaviruses and coronaviruses spike proteins were the top TREM peptide, suggesting that pre-existing immunity against SARS-CoV-2 in Vietnam was due to exposure to common cold coronaviruses. With limited immunity against emerging VOCs, further monitoring, and control of the epidemic, along with COVID-19 vaccine programs against VOCs, are necessary.


Asunto(s)
COVID-19 , SARS-CoV-2 , Humanos , SARS-CoV-2/genética , COVID-19/epidemiología , Vacunas contra la COVID-19 , Vietnam/epidemiología , Pandemias , Estaciones del Año , Glicoproteína de la Espiga del Coronavirus/genética , Epítopos , Anticuerpos Neutralizantes , Anticuerpos Antivirales
6.
Micromachines (Basel) ; 14(5)2023 May 18.
Artículo en Inglés | MEDLINE | ID: mdl-37241692

RESUMEN

Polymer-based micro-optical components are very important for applications in optical communication. In this study, we theoretically investigated the coupling of polymeric waveguide and microring structures and experimentally demonstrated an efficient fabrication method to realize these structures on demand. First, the structures were designed and simulated using the FDTD method. The optical mode and loss in the coupling structures were calculated, thereby giving the optimal distance for optical mode coupling between two rib waveguide structures or for optical mode coupling in a microring resonance structure. Simulations results then guided us in the fabrication of the desired ring resonance microstructures using a robust and flexible direct laser writing technique. The entire optical system was thus designed and manufactured on a flat base plate so that it could be easily integrated in optical circuits.

7.
Molecules ; 28(5)2023 Feb 27.
Artículo en Inglés | MEDLINE | ID: mdl-36903469

RESUMEN

Soil heavy metal contamination is a severe issue. The detrimental impact of contaminated heavy metals on the ecosystem depends on the chemical form of heavy metals. Biochar produced at 400 °C (CB400) and 600 °C (CB600) from corn cob was applied to remediate Pb and Zn in contaminated soil. After a one month amendment with biochar (CB400 and CB600) and apatite (AP) with the ratio of 3%, 5%, 10%, and 3:3% and 5:5% of the weight of biochar and apatite, the untreated and treated soil were extracted using Tessier's sequence extraction procedure. The five chemical fractions of the Tessier procedure were the exchangeable fraction (F1), carbonate fraction (F2), Fe/Mn oxide fraction (F3), organic matter (F4), and residual fraction (F5). The concentration of heavy metals in the five chemical fractions was analyzed using inductively coupled plasma mass spectroscopy (ICP-MS). The results showed that the total concentration of Pb and Zn in the soil was 3023.70 ± 98.60 mg kg-1 and 2034.33 ± 35.41 mg kg-1, respectively. These figures were 15.12 and 6.78 times higher than the limit standard set by the United States Environmental Protection Agency (U.S. EPA 2010), indicating the high level of contamination of Pb and Zn in the studied soil. The treated soil's pH, OC, and EC increased significantly compared to the untreated soil (p > 0.05). The chemical fraction of Pb and Zn was in the descending sequence of F2 (67%) > F5 (13%) > F1 (10%) > F3 (9%) > F4 (1%) and F2~F3 (28%) > F5 (27%) > F1 (16%) > F4 (0.4%), respectively. The amendment of BC400, BC600, and apatite significantly reduced the exchangeable fraction of Pb and Zn and increased the other stable fractions including F3, F4, and F5, especially at the rate of 10% of biochar and a combination of 5:5% of biochar and apatite. The effects of CB400 and CB600 on the reduction in the exchangeable fraction of Pb and Zn were almost the same (p > 0.05). The results showed that CB400, CB600, and the mixture of these biochars with apatite applied at 5% or 10% (w/w) could immobilize lead and zinc in soil and reduce the threat to the surrounding environment. Therefore, biochar derived from corn cob and apatite could be promising materials for immobilizing heavy metals in multiple-contaminated soil.


Asunto(s)
Metales Pesados , Contaminantes del Suelo , Zea mays , Apatitas , Ecosistema , Plomo , Contaminantes del Suelo/análisis , Metales Pesados/química , Carbón Orgánico/química , Suelo/química
8.
Environ Sci Pollut Res Int ; 30(20): 58866-58881, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-37002514

RESUMEN

Green knowledge sharing and behaviors are vital for organizations to implement green supply chain management and promote green entrepreneurship. These solutions support firms to understand market and customer needs through which they are able to carry out the practices which strengthen their sustainability. By realizing the significance, the research develops a model which integrates the concept of green supply chain management, green entrepreneurship, and sustainable development goals. The framework also builds to evaluate the moderating role of green knowledge sharing and employee green behavior. Proposed hypotheses are tested in the sample Vietnamese textile managers, and PLS-SEM methodology was employed to evaluate the model reliability, validity, and association among constructs. Generated results reveal the positive impact of green supply chain and green entrepreneurship on sustainable environment, and results also reveal that green knowledge sharing and employee green behavior both have the potential of being a moderator which enhances the relationship among outlined constructs. The revelation provides important insights for organizations to look into these parameters in order to achieve sustainability in a longer run.


Asunto(s)
Emprendimiento , Desarrollo Sostenible , Conservación de los Recursos Naturales , Reproducibilidad de los Resultados , Vietnam
9.
Nanomaterials (Basel) ; 12(7)2022 Mar 22.
Artículo en Inglés | MEDLINE | ID: mdl-35407161

RESUMEN

This paper summarizes some of the essential aspects for the fabrication of functional devices from bottom-up silicon nanowires. In a first part, the different ways of exploiting nanowires in functional devices, from single nanowires to large assemblies of nanowires such as nanonets (two-dimensional arrays of randomly oriented nanowires), are briefly reviewed. Subsequently, the main properties of nanowires are discussed followed by those of nanonets that benefit from the large numbers of nanowires involved. After describing the main techniques used for the growth of nanowires, in the context of functional device fabrication, the different techniques used for nanowire manipulation are largely presented as they constitute one of the first fundamental steps that allows the nanowire positioning necessary to start the integration process. The advantages and disadvantages of each of these manipulation techniques are discussed. Then, the main families of nanowire-based transistors are presented; their most common integration routes and the electrical performance of the resulting devices are also presented and compared in order to highlight the relevance of these different geometries. Because they can be bottlenecks, the key technological elements necessary for the integration of silicon nanowires are detailed: the sintering technique, the importance of surface and interface engineering, and the key role of silicidation for good device performance. Finally the main application areas for these silicon nanowire devices are reviewed.

10.
Chemosphere ; 298: 134276, 2022 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-35278449

RESUMEN

Zeolite is known to uptake toxic metals and filter nitrogenous waste from aquaculture effluents. The present study aimed to investigate the impacts of zeolite in three different applications namely, dietary zeolite (DZ), suspended zeolite (SZ) in the water column, and a combination of both (DZSZ) relative to unexposed freshwater crayfish, marron (control). At the end of the 56-days trial, the impact was assessed in terms of characterization of microbial communities in the culture environment and the intestine of marron. Alongside the microbial communities, the innate immune response of marron was also evaluated. The 16S rRNA data showed that marrons exposed to the suspended zeolite had a significant increase of bacterial diversity in the gut, including the restoration of marron core operational taxonomic units (OTUs), relative to other forms of exposures (DZ, DZSZ) and the control. Suspended zeolite alone also increased the number of unshared OTUs and genera, and improved predicted metabolic functions for the biosynthesis and digestion of proteins, amino acids, fatty acids, and hormones. In the tank sediment, the shift of microbial communities was connected more strongly with the time of experiment than the type of zeolite exposure. In the second case, only control marron had a different microbial ordination in terms of rare taxa present in the community. Nevertheless, the modulation in the gut environment was found more prominent in DZ, relative to modulation in the tank sediments. The taxa-environment correlation identified Rhodoferax as the most potential bacteria in removing nitrogenous waste from the rearing environment. Further analysis showed that SZ resulted in the upregulation of genes associated with the innate immune response of marron. Overall results suggest that SZ can be used to enrich microbial communities in the gut and tank sediments and better immune performance of marron.


Asunto(s)
Microbiota , Zeolitas , Alimentación Animal/análisis , Animales , Astacoidea/fisiología , Agua Dulce , Nitrógeno , ARN Ribosómico 16S/genética
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA